Insulation support and wire guide for an electrical connector



Dec. 5, 1967 J. F. GILLESPIE 3,356,987

INSULATION SUPPORT AND WIRE GUIDE FOR AN ELECTRICAL CONNECTOR Filed Aug.10, 1966 "United States Patent '0 3,356,987 INSULATION SUPPORT AND WIREGUIDE FOR AN ELECTRICAL CONNECTOR Francis Gillespie, Palmyra, Pa.,assignor to AMP Incorporated, Harrisburg, Pa. Filed Aug. 10, 1966, Ser.No. 571,562 5 Claims. (Cl. 339-223) This invention relates to a terminalused in connecting a wire thereto. The present terminal has means tosupport the wire where it joints the terminal so as to prevent unduebending stresses which normally concentrate at that point. This supportmeans is disclosed in US. Patent No. 2,405,111, and comprises a metalsleeve fitted over the terminal ferrule. More particularly, the presentinvention relates ot the above terminal having funneling means to guidethe wire into place in the terminal.

In high speed applications where pre-stripped lead wires areautomatically applied to terminals by transfer mechanism of applicationtooling, some of the outer strands of the lead wires extend outwardlyfrom the gathered strands. These strands fan out and prevent the leadwires from entering the crimping area of the terminal ferrule. In caseswherein lead wires with solid conductors are usd, the ends of theconductors sometimes become bent and misaligned or are flattened at thepoint of cut-ofi. Since the lead wires are being automatically insertedinto the terminals at such a rapid rate of speed, improper insertion ofone lead wire into its corresponding terminal causes an impropercrimping to occur and quite frequently causes the machine to jam.

Heretofore, terminals of the general type to which this invention isconcerned, have been in commercial use and include funnels directlybehind the crimping ferrules thereof. In these terminals, the funnel ison the insulation support sleeve and is defined by a V or U-shapedannular indent. The construction of the funnel in these terminals isunsatisfactory in a number of respects, among which are the following:the V or U-shaped groove weakens the terminal assembly particularly whena portion of the insulation sleeve is expanded for larger wire sizes;the bonding between the insulation support sleeve and the insulationthereon does not occur therebetween at the location of the groove; lesscrimping area is obtained; and the application of the insulation ontothe insulation support sleeve is difiicult because of the groove.

In the present invention, an annular projection is integrally formed inthe insulation sleeve directly behind the wire entry end of the ferrule.This projection is double in thickness, and is directed inwardly towardsthe ferrule so as to guide a conductor into a crimping position withinthe crimping area of the terminal.

It is, therefore, a principal object of the present invention to providea terminal as described above having funneling means with the insulationsupport sleeve to gather the strands of a lead wire and guide all ofthem into the terminal barrel.

Another object is the provision of a new and improved terminal which notonly has a wire guide formed on its insulation support sleeve but has astrengthened support sleeve which will not buckle or collapse during themanufacture or use thereof.

Another object is to provide a terminal having more support area betweenan insulation support sleeve and the insulation jacket of a wire.

Another object is the provision of a terminal having more bonding areabetween an insulation support sleeve and an outer insulation sleeve.

Still another object is to provide a new and improved terminal having asubstantially large flat crimping area not interrupted by large groovesand notches.

James 3,355,937 Patented Dec. 5, 1967 ice A further object is to providea terminal wherein the outer insulaiton sleeve is easier to assemble tothe terminal by virtue of a substantially uniform exterior surface onthe insulation support sleeve.

Other objects and attainments of the present invention will becomeapparent to those skilled in the art upon a reading of the followingdetailed description when taken in conjunction with the drawings inwhich there are shown and described illustrative embodiments of theinvention; it is to be understood, however, that these embodiments arenot intended to be exhaustive nor limiting of the invention but aregiven for purposes of illustration in order that others skilled in theart may fully understand the invention and the principles thereof andthe manner 01 applying it in practical use so that they may modify it invarious forms, each as may be best suited to the conditions of aparticular use.

The foregoing and other objects are achieved by a preferred embodimentof an electrical connector comprising a contact section and a ferrulesection, a sleeve having a first section and a second section, the firstsection disposed on the ferrule section, the second section having aninwardly-directed annular fold including a forward part and an adjacentrearward part disposed substantially parallel with respect to eachother, the annular fold extending toward the ferrule section at an anglewith respect to a longitudinal axis of the ferrule section and providedwith an inner end terminating adjacent an inner end of the ferrule, theannular fold defining a funnel.

In the drawings:

FIGURE 1 is a longitudinal cross-sectional View of a terminal inaccordance with the invention;

FIGURE 2 is a view similar to that of FIGURE 1 but showing a wireentered therein;

FIGURE 3 is a view of the terminal of FIGURE 1 after crimping; and

FIGURE 4 is a View similar to FIGURE 1 but showing a portion of theterminal expanded.

Referring now to the drawings and more particularly to FIGURE 1, anelectrical terminal T according to the present invention comprises aterminal connector or contact section 2 of the apertured-tongue typeincluding a wire barrel or ferrule portion 4 coextensive therewith. Athin metal insulation support sleeve 6 surrounds barrel 4 and extendsfrom the wire entry end thereof. An insulation sleeve 8 of suitabledielectric material is bonded or secured to support sleeve 6constituting a pre-insulated electrical terminal. The inside surface offerrule portion 4 is preferably serrated and the entrance thereto has anarcuate configuration.

Support sleeve 6 has a funnel 10 defined by an inwardly-directed annularprojection or fold having tapered walls which converge toward ferrule 4.It is desirable that these walls be in engagement but manufacturingtolerances may provide a slight gap between walls of some funnels whichis still acceptable. Funnel 10 primarily guides a conductor into properplace in barrel 4 and secondarily acts as a stop means to positionsleeve 6 onto barrel 4. Sleeves 6 and 8 along ferrule portion 4 areslightly reduced in diameter to secure these sleeves on the ferruleportion. The inside diameter of funnel '10 is slightly larger than theinside diameter of ferrule portion 4.

Funnel 10 is formed by first indenting the sleeve 6 from the side whileit spins on two mandrels which are disposed within the sleeve in spacedrelationship. With the side indenting tool removed, one mandrel is heldstationary while the other mandrel is moved axially towards the indent.This arrangement collapses the indent and directs its wall toward oneend. Sleeve 6 is hardened during the formation of the funnel. Afterfunnel -10 has been formed in sleeve 6, an annealing operation isperformed on sleeve 6 to insure against the sleeve splitting duringcrimping. The resultant funnel is stronger by virtue of the adjacentwalls. The sleeve may then be'plated and the insulation sleeve isapplied to the non-plated or plated sleeve.

Referring now to FIGURE 2, the conductor C of a wire W is easily guidedinto the center of wire barrel 4 because strands of the conductor whichmay previously have been fanned outwardly, through handling, have beenpointed and directed into barrel 4.

Referring to FIGURE 3, a terminal is cold forged onto a wire W andconductor C to effect an electrical and mechanical connection. One crimpA is made directly over wire barrel 4 and another crimpB is made onto aportion of sleeve 6 which contains the insulation jacket of wire W.During crimping, funnel 10 is deformed little if any from its originalshape.

FIGURE 4 illustrates a modified form of the invention wherein portionsof sleeves 6 and 8 are expanded radially. This is done so that wireswith substantially larger insulation jackets may be terminated.Expansion is usually dine by forcing an oversize mandrel into therearward end 12 of sleeves 6 and 8. In prior terminals, the expansioncaused V or U shaped wire guides to collapse or become deformed to thepoint where they were no longer operable as wire guides. In the presentinvention, double walls of funnel 10 along with the acute angle of thefunnel strengthen the wire guide and prevent its deformation duringexpansion.

It has been found that terminals, according to this invention, can becrimped at relatively high pressures with no detrimental effect to theconnection. Funnel 10 is directed inwardly toward barrel 4 atapproximately a 30 angle, therefore any excessive crimping pressure willcause the funnel to tend to flatten rather than bite into conductor C.

It should be pointed out that the present invention may be used inconjunction with connectors to splice wirestogether as well as thesupport sleeve without any insulation sleeve thereon. It should also befurther pointed out that the present invention is directed toautomatically feeding wires into the sleeve and barrel portionsofterminals but that the configuration of the funnel means is equallyapplicable and advantageous to hand tool application.

It will, therefore, be appreciated that the aforementioned and otherdesirable objects have been achieved; however, it should be emphasizedthat the particular embodiments of the invention, which are shown anddescribed herein, are intended as merely illustrative and not asrestrictive of the invention.

The invention is claimed in accordance with the following:

1. In an electrical connector, the combination comprising a wire barreladapted to receive a wire conductor,

a sleeve fitted to and extending beyond the mouth end of "saidbarreltosupport a wire where -it'joins'said barrel,

an annular projection in said-sleeve, said projection having a forwardedge disposed adjacent the opposite end of the barrel to position saidsleeve onto said barrel and a rearward transitional slope definingfunnel means together andpoint all strands of said conductor towards-thecenter of said projection and guide said conductor into said barrel,said'proje'ction having an inside diameter slightly larger than theinside diameter of said barrel, said projection having a doublewallsection to strengthen said funnel.

2. A connector according to claim 1 wherein said transitional slope hasan approximate 30 taper.

3. A connector according to claim 1 wherein said extending portion ofsaid metallic sleeve is expanded.

4. An electrical connector comprising a wire barrel adapted to receive awire conductor, a metallic sleeve fitted to and extending beyond themouth end of said barrel to support a wire where it joins said barrel,and an insulation sleeve over said metallic sleeve, an annularprojection in said sleeve, said projection having a forward edgedisposed adjacent the opposite end of the barrel to position said sleeveonto said ferrule and a rearward transitional slope defining funnelmeans to direct said conductor towards the center of said projection andguide said conductor into said barrel, said projection having an insidediameter slightly greater than the inside diameter of said barrel, saidprojection having a double wall section in combination with an acutebend of material to strengthen said funnel.

5. An electrical connector comprising a contact section and a ferrulesection, a sleeve having a first section and a second section, the firstsection disposed on the terrule section, the second section having aninwardly-directed annular fold including a forward part and an adjacentrearward part disposed substantially parallel with respect to eachother, the annular fold extending toward the ferrule section at an anglewith respect to a longitudinal axis of the ferrule section and providedwith an inner end terminatingadjacent an inner end of the ferrule, theannularfold'defining a funnel.

References Cited UNITED STATES PATENTS 2,405,111 8/1946 Carlson et al339-223 2,410,321 10/1946 Watts 339-276 2,823,250 2/1958 -OKeefe 339-2762,939,905 6/1960 Canfield 339223 MARVIN A. CHAMPION, Primary Examiner.

R.'S. STROBEL, Assistant Examiner.

1. IN AN ELECTRICAL CONNECTOR, THE COMBINATION COMPRISING A WIRE BARRELADAPTED TO RECEIVE A WIRE CONDUCTOR A SLEEVE FITTED TO AND EXTENDINGBEYOND THE MOUTH END OF SAID BARREL TO SUPPORT A WIRE WHERE IT JOINSSAID BARREL, AN ANNULAR PROJECTION IN SAID SLEEVE, SAID PROJECTIONHAVING A FORWARD EDGE DISPOSED ADJACENT THE OPPOSITE END OF THE BARRELTO POSITION SAID SLEEVE ONTO SAID BARREL AND A REARWARD TRANSITIONALSLOPE DEFINING FUNNEL MEANS TOGETHER AND POINT ALL STRANDS OF SAIDCONDUCTOR TOWARDS THE CENTER OF SAID PROJECTION AND GUIDE SAID CONDUCTORINTO SAID BARREL, SAID PROJECTION HAVING AN INSIDE DIAMETER SLIGHTLYLARGER THAN THE INSIDE DIAMETER OF SAID BARREL, SAID PROJECTION HAVING ADOUBLE WALL SECTION TO STRENGTHEN SAID FUNNEL.